Condenser (capacitor) microphones differ from dynamic and ribbon microphones because they are not self-generating. That is, they cannot generate electricity in response to an impinging sound wave. A condenser microphone modifies an external source of electricity to reflect the effects of a sound wave striking its diaphragm. Dynamic and ribbon microphones use magnetism to generate electricity in response to a sound wave: they are self-generating. Furthermore, both of these types of microphones are inherently low impedance devices. It is possible to connect a dynamic microphone element directly to a balanced, low-impedance mixer input. Many commercially made dynamic microphones do just that.
On the other hand, a condenser micorphone is an inherently high-impedance device. How high? Verrrrrrry high. On the order of a billion ohms (1 Gigaohm). This is high enough that the inherent capacitance of a foot of shielded cable would audibly reduce the output of the microphone. (the cable capacitance and the capsule capacitance form a capacitive voltage divider) All condenser microphones have an impedance converter, in the form of a vacuum tube or field-effect transistor (FET), built into the microphone, and located extremely close to the microphone element. The impedance converter and the microphone element itself require an external power source. ‹‹ To be strictly correct, electret condenser microphones are a bit different as the microhone element does not require a power source for operation (it is more or less permanently self polarized). Regardless, the impedance converter still requires an external source of power. ››
What is it, exactly?
The obvious external power source for any modern microphone is a battery. About the only electronic advantage that a battery has is that its output is pure DC. The only other advantage (to the battery company) is that you have to keep on buying them.
Tube microphones require several different voltages for operation. This invariably means a multi-conductor cable and non-standard (not XLR) connectors. A tube microphone will almost always have an associated external power supply.
In the late 1960s, Neumann (you know, the folks that brought you the U47 and U87 microphones) converted its microphones to solid-state, adopting a system of remote powering that they called, and trademarked, Phantom Powering. Because of the trademark, some manufacturers use terms like Simplex Powering, etc. Over the years, the trademark has become genericized and now refers to any device that is powered according to DIN standard 45 596. ‹‹ Neumann says that they gave the use of the trademark to public domain. ››
Types of Microphones
The terms Omni-directional---uni-directional---
cardioid--& super cardiod refer to the polar pattern.
Basically--if you are looking at the microphone as it is laying on it's side,the ploar pattern shows how tight the pattern is and how much unwanted sound is rejected.
The super cardioid is the tightest and the cardioid is next.
Some of the cardioids are very close in pattern to the supercardioid mics.
If you are a vocalist and are concerned about quality,then I recommend the following mics:
1---Samson CO5 CL--Cardioid-condenser--40-16k--about $70. This is the best bang for the buck